Off the charts is an idiom that means something is exceptionally good or bad. It is often used to describe something that is extremely popular or successful, or something that is very UNPOPULAR or unsuccessful. In this crossword, the solutions UNLISTED (8 letters), EXTREME (7 letters), and UNPOPULAR (9 letters) all refer to the term off the charts. UNLISTED means not included in a list or directory, EXTREME means of a high degree or intensity, and UNPOPULAR means not liked or approved by many people. Together, these three words can be used to describe something that is not included in a list, of a high degree or intensity, and not liked or approved by many people.